Displays used in airborne applications and other harsh environments must be sufficiently ruggedized so as to allow for component survival in vibration and shock events. Additionally, displays used in aircraft must provide sufficient stiffness to reinforce a touchscreen interface or survive an inadvertent palm bracing by a user during a turbulence event. Traditional means of stiffening an optical display stack add unwanted weight and cost. Adding to such challenges, displays produce a significant amount of heat that needs to be dissipated for proper functioning of the display.
Over the last few decades, almost all harsh environment display applications have utilized liquid crystal display (LCD) technology. LCD technology uses a switchable matrix with liquid crystal interaction to regulate light through a transmissive color filter. LCD technology must be illuminated by a separate light source from behind (e.g., from a backlight) in order to present readable information to the user. LCD technology requires heavy and costly, optically indexed and transmissive (clear) adhesive and/or glass components to be used to stiffen the optical stack in addressing the environmental hardening needs for harsh environment applications. Typically, such structural enhancements must be free spanning, which further compounds the weight increase. Such a technique, though necessary for backlit display technologies, proves inefficient by offering diminishing returns because substantial weight must be added for little stiffness improvement. Typically, monolithic glass substrates are the only economical option for LCD display technology utilized in harsh environments. Additionally, the stiffening components, which are typically adhered to the LCD display, result in low yield issues caused by visible contaminants due to the transmissive nature of the LCD technology and requisite backlit illumination. Such LCD technology yield issues result in increased cost.